Pitman stirrup bearing



May 1, 1934- J. P. RATlGAN PITMAN STIRRUP BEARING Filed June 30, 1930 Patented May 1, 1934 UNITED STATS PA'E'ET OFFICE 5 Claims.

This invention relates to pitman stirrup bearings, a type of construction used in connection with walking beams for operating deep well pumps.

An important object of this invention is to avoid wear of the walking beam by the stirrup that connects the walking beam with the pitman.

Another object is to prevent the stirrup from laterally shifting to such an extent that it would scrape and wear the sides of the walking beam and produce excessive friction between the stirrup and the walking beam.

Another object is simplicity and ruggedness of construction.

Other objects and advantages will appear in the subj oined detailed description.

The accompanying drawing illustrates the invention:

Figure l is a plan view of a pitman stirrup bearing constructed in accordance with the provisions of this invention. Fragments of a walking beam and stirrup are indicated in broken lines.

Figure 2 is a front elevation of Fig. l, a portion of the pitman being broken away.

Figure 3 is a horizontal section on the line indicated by 33, Fig. 1.

Fig. 4 is a vertical section on the line indicated by 44, Fig. 1.

Referring to the drawing, there is provided a channeled member 4 which may be secured to the upper face of the walking beam, indicated at A, by any suitable means. In this instance the member 4 is provided with a number of vertically extending bolt holes 5 through which extend bolts 1 6 that pass into or through the walking beam,

The channel in the member 4 is indicated at '7 and, in this instance, is concave in form.

Rockably resting on the bottom 8 of the channel 7 is a member 9 that is, preferably, of less diameter than the channel so that a free rocking movement or oscillation of the member 9 can occm', the plane of oscillation being longitudinally of the member 4 or, in other words, transversely of the channel. The underface of the member 9 is convex and, in this instance, said member 9 is substantially of cylindrical form. Suitable means are provided for securing the member 9 to a stirrup, indicated in broken lines at B. The stirrup B is commonly employed for connecting the walking beam to the I pitman that is employed for driving the walking beam, and it is common practice to rest the stirrup on the upper face of the walking beam or on a wooden block mounted on said upper face. When the stirrup is mounted on the walking beam, it wears a deep groove in the walking beam and ulti- (Cl. BUS-21) mately damages the walking beam to such an extent that said walking beam must be discarded. When the stirrup is mounted on a block, it usually happens that the block is worn through before it is noticed by the operator, and the walking beam is damaged by the stirrup wearing a groove therein as above mentioned. In the present instance, the member 9 is provided in its upper face with a channel 10 extending longitudinally of said member 9 and the means at present employed by me for securing the member 9 to the stirrup is constructed as follows. At each end of the member 9 and integral therewith is a pair of opposed upstanding flanges 11, and the stirrup B passes between the flanges of each pair. The flanges are provided with transversely extending bolt holes 12 through which pass bolts 13. When the bolts are tightened, the flanges of each pair are drawn toward one another so as to tightly clamp upon the stirrup, thus fixing the member 9 to the stirrup so that relative movement will not take place between the member 9 and the stirrup. When the stirrup swings the member 9 rocks upon the member 4.

The member 4 is provided upon opposite sides of the channel 7 with oil reservoirs 14, 15 which communicate through ports 16 with the channel 7. Preferably, grooves 17 extend transversely of the channel 7 in the bottom 8 thereof, and the opposite ends of said grooves 1'7 communicate with the ports 16. Thus lubricant C, supplied to the reservoir 15 through an opening or openings 18 in the top thereof, flows through the ports 16 into the grooves 17 and thence spreads over the bottom 8 of the channel 7 so as to thoroughly lubricate said bottom and the member 9, thereby minimizing wear of the bearing surfaces.

When that end of the walking beam, on which the stirrup bearing is placed, is lowered to a lower level than it occupies in the normal working stroke of the walking beam, as occurs, for example, when the pump is being pulled, the lubricant will flow into the reservoir 14 and, accordingly, will not spill out of the channel 7; and, when the pump is then returned to its working position, the lubricant can flow out of the reservoir 14 into the channel 7.

Inorder to insure against the member 9 jumping out of the channel 7, there is preferably provided a bridging member 19 that bridges over the channel '7 midway between the pairs of flanges 11. The member 19 is inverted U-shaped in form and is provided at its opposite ends with bolt holes 20 through which pass bolts 21. Or

an equivalent fastening means may be provided for the member 19. The bolts 21 pass through vertical holes 22 provided in the member 4. Normally, the member 19 does not contact with the member 9 but in case there is a tendency for the member 9 to leave the channel 7, the member 19 would prevent such an occurrence.

The channel '7 is provided at its opposite ends with upstanding abutments 23 which function to limit endwise movement of the member 9, thus preventing scraping of the side arms of the stirrup B against the side faces of the walking beam. The distance between the inner faces of the abutments 23 is somewhat greater than the length of the member 9 so that some lateral motion of the stirrup can occur. These abutments 23, in this instance, constitute end walls for the channel so as to prevent oil flowing from the ends of the channel '7. In this instance, the end walls 23 are substantially of the same height as the side walls 24 of the channel '7.

The foregoing will make clear the construction and operation of the invention and, briefly stated, the operation is as follows: The various parts being assembled in place, as hereinbefore described and, assuming that the pitman, not shown, is operating, in the manner well understood in this art, the stirrup B will be swung by the action of said pitman so as to be given a pendulum-like motion, thus rocking or oscillating the member 9 in the channel 7. When the pitman descends and draws the stirrup downwardly, the pressure of said stirrup on the member 4 will be transmitted to the walking beam so as to pull down that end of the walking beam with which the stirrup is connected. The weight of the pump rods and liquid being pumped will normally move the pitman end of the walking beam upwardly, thus maintaining the member 9 seated in the channel 7. However, in event of the movement of the pitman being faster than the movement of the beam, when the pump is making its down stroke, the member 9 will be retained in the channel '7 by the bridging member 19. When, for any reason, it becomes advisable to disconnect the stirrup from the walking beam, this may be easily effected by simply removing the bolts 21, taking off the bridging member 19, and lifting off the member 9, together with the stirrup secured to said member 9. The abutments or end walls 23 prevent the sides of the stirrup from rubbing against the sides of the walking beam, thus avoiding wear of the walking beam and stirrup and liability of breakage of the stirrup, due to wear.

It is to be understood that the invention may be used just as readily at the pump end of the beam for connecting the pump rod thereto.

I claim:

1. A pitman stirrup bearing comprising a channeled member, having a relatively wide concaved channel closed at its ends, a relatively narrow member rockably resting on the bottom of the channel, and a means to secure a stirrup on the upper face of the second mentioned member, the channeled member provided with an oil reservoir on one side of the channel and said channel member having a port freely communicating the reservoir with the channel.

2. A pitman stirrup bearing comprising a channeled member, a member rockably resting on the bottom of the channel, a means to secure a stirrup on the upper face of the second mentioned member, and an inverted U-shaped member detachably secured to the first mentioned member and bridging over the channel.

3. A pitman stirrup bearing comprising a channeled member, the channel being closed at its ends, said member provided with oil reservoirs on opposite sides of the channel and said channeled member having ports freely connecting the reservoirs with the channel, one of the reservoirs having an opening in its top, a member rockably resting on the bottom of the channel, and a means to secure a stirrup on the upper face of the second mentioned member.

4. A stirrup bearing including the combination of a channeled member, the channel being closed at its ends, said member provided with oil reservoirs on opposite sides of the channel and said channeled member having ports freely connecting the reservoirs with the bottom of the channel, a member journaled in the channel, and a means to secure a stirrup to said second mentioned member.

5. In a stirrup bearing, a channeled member, the channel thereof being closed at its ends, said member provided with an oil reservoir on one side of the channel and said channeled member having ports freely connecting the reservoir with the bottom of the channel, and a stirrup supporting member journaled in the channel.

JAMES P. RATIGAN. 

